Robotic arm and wrist mechanisms
AssigneeiRobot Corporation
InventorsMark R. Claffee, Timothy R. Ohm, Erik Amaral, Annan M. Mozeika
Life of this patent
Estimating the term…
Abstract
A robot includes a support, a movable member coupled to the support to permit gimbal rotation about a pitch axis and a yaw axis, and first and second linear actuators connected to each of the support and the movable member and operable to rotate the movable member about the pitch axis and the yaw axis. The first linear actuator is pivotally attached to the movable member at a first pivot point. The second linear actuator is pivotally attached to the movable member at a second pivot point. The first and second pivot points are each angularly offset from the pitch axis and the yaw axis by about 45 degrees and are located on the same side of the pitch axis.
Claims13
A robot comprising:
- a support;
- a movable member coupled to the support to permit gimbal rotation about a pitch axis and a yaw axis;
- and
- first and second linear actuators connected to each of the support and the movable member and operable to rotate the movable member about the pitch axis and the yaw axis;
- wherein:
- the first linear actuator is pivotally attached to the movable member at a first pivot point;
- the second linear actuator is pivotally attached to the movable member at a second pivot point;
- and
- the first and second pivot points are each angularly offset from the pitch axis and the yaw axis by about 45 degrees and are located on the same side of the pitch axis;
- and
- wherein the first and second linear actuators each include:
- a lead screw having a lead screw longitudinal axis and including a lead screw thread;
- and
- a drive nut assembly including:
- a guide holder;
- and
- first, second and third guide bearing assemblies each including:
- a rotation bearing mounted on the guide holder;
- and
- a plurality of annular guide ribs on the rotation bearing, wherein the rotation bearing permits rotation of the guide ribs about a guide axis relative to the guide holder and the lead screw;
- wherein the guide axis forms an oblique cant angle with the lead screw longitudinal axis;
- wherein the first, second and third guide bearing assemblies are serially disposed along the lead screw longitudinal axis and the oblique cant angle of the second guide bearing assembly is opposite the oblique cant angles of the first and third guide bearing assemblies;
- and
- wherein the guide ribs are mated with the lead screw thread such that rotation of the lead screw is converted to thrust on the guide holder.
A linear actuator comprising:
- a lead screw having a lead screw longitudinal axis and including a lead screw thread;
- and
- a drive nut assembly including:
- a guide holder;
- and
- first, second and third guide bearing assemblies each including:
- a rotation bearing mounted on the guide holder;
- and
- a plurality of annular guide ribs on the rotation bearing, wherein the rotation bearing permits rotation of the guide ribs about a guide axis relative to the guide holder and the lead screw;
- wherein the guide axis forms an oblique cant angle with the lead screw longitudinal axis;
- wherein the first, second and third guide bearing assemblies are serially disposed along the lead screw longitudinal axis and the oblique cant angle of the second guide bearing assembly is opposite the oblique cant angles of the first and third guide bearing assemblies;
- and
- wherein the guide ribs are mated with the lead screw thread such that rotation of the lead screw is converted to thrust on the guide holder.
Dependencies are inferred from the claim text.